Gas barrier properties are one of the key requirements for polymers used in packaging applications to protect the contents and provide desired shelf-life. The prevention of oxygen permeation, for example inhibits oxidation and microbial growth, whereas prevention of water vapor permeation retains liquid content. Many polymers have emerged for these applications such as poly(ethylene terephthalate) (PET), polyethylene (PE), poly(vinyl alcohol) (PvOH), ethylene vinyl alcohol polymer (EvOH), poly(acrylonitrile) (PAN), poly(ethylene naphthalene) (PEN), polyamide derived from adipic acid and m-xylenediamine (MXD6) and poly(vinylidene chloride) (PVdC), and may include additives to enhance barrier properties. However, most of these polymers suffer from various drawbacks. For example, high density polyethylene (HDPE) and low density polyethylene (LDPE) have fair water vapor barrier, but poor oxygen barrier. EvOH exhibits good oxygen barrier at low humidity levels but fails at high levels of humidity. PET has relatively high tensile strength but is limited by low gas barrier properties. Blending PET with high barrier polymers such as poly(trimethylene furandicarboxylate) (PTF) is a solution to reducing resin cost while still potentially improving barrier properties and has been reported in literature. However, chemical incompatibility can lead to phase separation and inhomogeneous physical properties.
Hence, there is a need for new compositions comprising transesterified furan-based polyesters formed by melt blending of poly(alkylene furandicarboxylate) with poly(alkylene terephthalate) that can enhance chemical compatibility and provide distinct properties over physical blends.